1. Field
Aspects of the present invention relate to an apparatus for thermally processing a substrate, and more particularly, to an apparatus for thermally processing a substrate capable of minimizing a temperature distribution in a process chamber and uniformly supplying heat to the entire region of the substrate.
2. Description of the Related Art
In recent times, techniques for manufacturing semiconductor devices and display devices have been developed to improve integrity, reliability, response time, etc., in order to meet with consumers' various needs. In general, semiconductor devices and display devices are manufactured by sequentially performing a series of unit processes such as deposition, photolithography, etching, ion implantation, diffusion, etc., on substrates.
Several of the unit processes may be performed in a substrate thermal processing apparatus such as a heating furnace. For example, a diffusion process, an annealing process, an oxidation process, a deposition process, etc., are performed in the substrate thermal processing apparatus.
The substrate thermal processing apparatus may generally be a vertical type furnace in which a quartz process chamber is installed in an inner space of a heater chamber, and substrates are processed in a high temperature atmosphere in the process chamber. The vertical type furnace employs a batch type furnace in which a plurality of substrates are received in a boat to be loaded into the process chamber at a time.
The heater chamber includes a plurality of heaters to evenly increase an inner temperature thereof. Here, the heaters are installed at sidewalls, a lower surface and an upper surface of the heater chamber. The heaters installed at the sidewalls of the heater chamber are disposed along an outer periphery of the heater chamber to surround the heater chamber in an elongated shape.
Since the heater has a circular shape whereas the substrates loaded into the process chamber have a rectangular shape, temperatures applied to sides and corners of the substrate may be different.
Since the heater chamber includes the heaters disposed in an elongated shape, it is impossible to heat only several regions according to the measured temperature distribution.
In addition, since the heater has an elongated shape, thermal expansion caused in proportion to its length may occur. Further, since the amounts of heat applied are different depending on positions of the rectangular substrate, the substrate may be deformed and the temperature distribution may be uneven.
Furthermore, if the temperature distribution is uneven, characteristics of the material formed on the substrate may be different depending on the positions thereof.